The Chan Chan Archaeological Zone, located near the city of Trujillo, Peru, is the site of the largest mud-brick city in the Americas and the capital of the Chimu civilization. Founded by the Chimu Empire in the 9th century A.D., the city was massive, covering more than 200 square kilometers. Known for its unique architectural style and complex urban layout, the palaces and urban fortresses at the site are known as “Ciudadelas” and demonstrate the hierarchical nature of the society and the highly developed construction techniques of the time. The mud-brick structures are threatened by climate change, but still retain a rich cultural and historical heritage, and in 2009, Ciudadelas was declared a World Heritage Site. Tourists can visit these well-preserved architectural sites to learn about the glorious history of the Chimú civilization, an important window into ancient South American culture.